III. Abstract of Research Plan for Extension Period (5 years) 1. To examine the role of co-repressors, e.g., HDAC, Sin3A, in menin-mediated inhibition of gastrin 2. To examine the role of somatostatin in regulation of co-repressors 3. To determine the role of somatostatin and menin in the regulation of p27 and cell proliferation. Role of MLL. Are duodenal gastrinomas of myeloid origin? RELEVANCE (See instructions): Relevance to publish health include furthering our understanding of peptic ulcer disease, neuroendocrine transformation and the molecular basis underlying the effects of SOM analogs used to treat neuroendocrine disorders.